In the eye care field, there are generally two types of devices currently used by eye care practitioners for occlusion of the eye. One such device is designed for transient use and is placed in front of the eye to block or modify its vision, enabling the vision tester to determine visual function of the unoccluded eye or interrelation of function between eyes. Transient occluders for ocular diagnostics are typically non-disposable and occlude or modify the vision in one eye. These occluders are usually hand-held and made of hard plastic, metal, or glass in the shape of a paddle, mask, or clip-on device. A non-disposable transient occluder of a smaller rounded shape is also used in trial spectacle frames or can be incorporated into a machine called a phoropter, used to determine a patient's refractive error for spectacle or contact lens prescriptions or to perform other optical or neuropthalmalogic testing.
Non-disposable transient occluders are problematic for several reasons. First, it is often difficult for the patient or practitioner to place the occluder in the correct position over the patient's eye for accurate vision testing. It is especially difficult for a practitioner to adequately occlude an infant's eye using a non-disposable transient occluder. Younger and elderly patients often lack the muscular coordination or patience to hold the occluder steadily in place. It is difficult for these patients to keep the hand-held occluder in proper position over the eye while undergoing vision testing. Elderly patients often have advanced arthritis, poor coordination, neurological tremors, or physical abnormalities of the head or neck causing them to have extreme difficulty in keeping the hand-held occluder properly positioned over the eye, and at the same time, sit behind the phoropter in proper position. Non-experienced vision testing agents, such as school visual screeners, non-medical practioners in mass screening projects or inexperienced eye technicians collect spurious vision testing data because of improperly placed non-disposable occluders.
In addition, use of trial frame occluders is time consuming and difficult when the practitioner wishes to quickly determine visual accuity. These problems lead to inaccurate visual function testing. This problem is compounded when the testing is done for longer time periods because the patient and practitioner become fatigued.
Non-disposable transient use occluders are made of a permanent hard material, such as plastic, metal, or glass. These recurrently-used occluders can transmit bacteria or viruses from patient to patient since they are reused. For example, diseases such as viral epidemic keratoconjunctivitis can be easily transmitted from patient to patient by reusing the non-disposable transient occluders, since they come in contact with the face and hands of successive patients. It has also been suggested that the human HIV virus, implicated in AIDS and ARC syndrome, can also be transmitted via bodily secretions, such as tears. The use of disposable transient occluders obviates this problem.
Another disadvantage of non-disposable transient occluders constructed of hard materials is their potential for scratching the delicate plastic lenses of spectacles or coated lenses.
Transient use occluders often distort vision by changing the effective optical power of spectacles, when pressure is placed on the spectacles by the occluder, thereby altering the position of the spectacles relative to the patient's eye. This distortion interferes with accurate visual testing and diagnosis, especially in patients whose vision is highly myopic, hyperopic, or astigmatic, or in patients who are aphakic, i.e., those who have had cataract extraction.
A second type of occluder designed for extended periods of wear, typically 2-48 hours, is used solely for treatment of vision abnormalities, not for diagnostic testing. These occluders are typically used in the treatment of strabismus (eye turn), amblyopia (lazy eye), and diplopia (double vision). This extended-wear occluder comes in the form of a complexly constructed eyepatch made of layered fabric, paper, or plastic, such as those disclosed in U.S. Pat. Nos. 4,793,003 and 3,068,863. These extended-wear occluders have a surrounding area of adhesive material, for placement on the periorbital tissue about the eye for relatively long periods of time and are typically disposable and replaced periodically. Their function is to keep the eye visually occluded and devoid of significant amounts of ambient light.
These extended-wear disposable occluders are constructed to adhere to the patient's periorbital tissue for hours to days at a time. These occluders are not designed for fast application, fast removal, disposable, transient use in that they are necessarily firmly attached to the face and adherent to the periorbital tissue for the full circumference of the patch. This makes their fast application and fast removal for disposable transient use inefficient and therefore infeasible. The extended-wear occluders are not designed for attachment directly to spectacles for vision testing. Moreover, they are too complex in design and construction and therefore, too expensive for fast application, fast removal, disposable, transient use. The extended-wear occluders must necessarily contain a type of adhesive, which often leaves a sticky residue on the skin after removal.
The extended-wear occluders are often designed so that a strip of adhesive maintains the eye beneath the occluder in a closed position. This requires careful application of the occluder so that the cornea (front surface of the eye) is not abraded by the overlying adhesive or occluder. In addition, these occluders are difficult to properly place. Because of their firm, prolonged, total adhesive occlusion of the eyes, the extended-wear occluders often cause allergic reactions to the patient's skin surrounding the eye, and sweating, irritative reactions due to prolonged wear of the occluder.
The primary objective of extended-wear occluders is to block as much vision and prevent as much light as possible from contacting the eye. Vision and light occlusive therapy are used to immobilize the non-affected eye while the uncovered affected eye is free to move in response to visual stimuli. It is believed that even small amounts of light passing through the extended-wear eye occluder to the amblyopic eye stimulates undesirable eye movement, thereby decreasing the efficacy of treatment. It is also believed that scleral transmission of light in the non-amblyopic eye aids in maintaining abnormal neuroconnections in the amblyopic eye, promoting and maintaining the amblyopic condition. Therefore, light occlusion is thought to be important for efficient treatment of this visual deficit.
Thus, extended-wear occluders are used to treat eye problems that require a substantially complete occlusion of vision and light. Examples of these extended-wear disposable occluders are disclosed in U.S. Pat. No. 4,793,003 to Riedel. Riedel discloses a light-occlusive, extended-wear, self-adherent eye occluder comprising an absorbent pad with a non-adherent lower surface, a thin microporous polymeric film overlying the upper surface of the pad, pressure-sensitive adhesive means to adhere the patch to the eye socket and a removable protective liner covering the non-adherent lower surface of the absorbent pad and the exposed portion of the pressure-sensitive adhesive. One of the primary features of the eye occluder disclosed in Riedel is that the polymeric film is capable of blocking at least 95% of the light from a preselect wavelength impinging on the film. By virtue of its intended function, the design and construction of this occluder is complex and relatively expensive to produce. Therefore, it is inadequate in its design and has economic constraints for transient, one-time use.
Another extended-wear, light-occlusive extended-wear product known as Opticlude.RTM. Orthoptic Eye Patch sold by 3M, comprises an absorbent pad having non-adherent films on its upper and lower surfaces. The patch is secured to the eye socket by use of a medical tape, and a removable liner protects the pad and adhesive layer prior to use. The Opticlude patch is said to effectively block about 75% of the incoming ambient light.
Another light-occlusive patch is sold in Europe by Beiersdorf and is known as Elastopad-lite occlusive plaster. This product is a laminate comprising an absorbent pad, a layer of black non-woven material and a layer of porous polyvinyl chloride overlying the black non-woven layer. A piece of tape overlies the polyvinyl chloride layer and extends beyond the periphery of the other layers of the patch to adhere the patch to the eye socket. The Elastopad product is stated to block virtually all of the ambient light. However, it is uncomfortable in that it is thick and relatively nonconformable.
Other extended-wear devices are used to protect the eye from contact with objects or light after surgery or after a wound to the eye. For example, U.S. Pat. No. 3,068,863 to Bowman discloses a protective eye device which includes a protective patch having a convex outer edge extending downwardly and inwardly from the upper edge, a lower convex edge of shorter radius than the upper edge and the outer edge, and an inner concave edge extending from the lower edge to the other end of the upper edge to form a tab portion. The protective device of Bowman also discloses an adhesive layer on one side of the patch and a protective strip disposed on the adhesive layer intermediate the edges of the patch. The adhesive layer overlies the eyelid and holds it in closed position thereby preventing access of light to the eye.
U.S. Pat. No. 4,709,695 to Kohn discloses a protective device for the eye which includes an adhesive base that attaches to the patient's skin and surrounds the area to be protected. A protective covering is coupled to the base by adhesive or Velcro. The covering can be repeatedly decoupled and recoupled with the adhesive base without detaching the base from the patient's skin. The device thereby provides repeated access to the protected area without damaging the skin.
Accordingly, there exists a need for easy to apply and easy to remove, self-adherent, transient-use eye occluders for use in everyday visual function testing and treatment. There also exists a need for an easy to apply, easy to remove, transient occluder which is economical to manufacture so as to be disposable. A need also exists for a self-adherent transient eye occluder which is easy to position and remove, leaving minimal residual debris on the wearer's face or spectacles.
The eye occluder of the present invention is a self-adhering occluder which is designed to substantially block vision, yet not necessarily be light occlusive. It is primarily intended for use in performing short-term visual and neuroopthalmalogic diagnostic testing and treatment.
Accordingly, one object of the present invention is to provide a disposable, self-adherent, easy to apply and easy to remove, eye occluder which substantially blocks vision when placed over an eye and is used in performing visual function diagnostic testing and treatment, which does not require lid or eye immobilization and full eye occlusion.
A further object of the present invention is to provide a self-adherent eye occluder that can be disposed of after each use and does not transmit bacteria or viruses from patient, since it is not reused.
Another object of the present invention is to provide a self-adherent eye occluder which is easily placed by the patient or physician in proper position over the eye or directly on the spectacles, and which is easily removed, leaving no significant residual debris on the skin or spectacles.
A further object of the present invention is to provide a self-adherent eye occluder which does not change the effective optical power of spectacles when the occluder is placed directly on the spectacles of the wearer, and does not damage the optical qualities of the spectacles, once the occluder is removed.
Another object of the present invention is to provide a disposable eye occluder which does not cause allergic reactions to the eyes or skin of the wearer.
A further object of the present invention is to provide a disposable self-adherent eye occluder which is non-irritating and contains an adhesive which does not scratch or irritate the wearer's skin or spectacle lenses, when the eye occluder is placed thereon.
Another object of the present invention is to provide a self-adherent eye occluder for visual testing which does not need to be held in place by the patient, technician or other testing agent, or treating physician.
A further object of the present invention is to provide a self-adherent eye occluder for testing of patients' visual field and eye-muscle coordination.
Another object of the present invention is to provide a self-adherent eye occluder for visual testing negating refractive error, using pinhole and thin slit openings on the occlusive shield.
Another object of the present invention is to provide a self-adherent eye-occluder which supports refractive and diagnostic lenses.